pharm exam 2 GI meds Flashcards
What are the Antiemetic drugs
Scopolamine
Prochlorperazine
metocloperamide
Ondansetron
Dronabinol
Promethazine
Meclizine
Dimenhydrinate
What are the CTZ activation medications
Serotonin 5-HT2
Dopamine D2
Muscarinic M1 receptors
what are the drug categories for nausea and vomiting
cholinergic/muscarinic antagnoist
dopamine receptor antagonists
serotonin receptor antagonists
cannabinoids
histamine antagonists
What is the cholinergic antagonist
scopolamine
what is the MOA of Scopolamine
blocks Ach at parasympathetic sites (smooth muscle, secretory glands, CNS)
also reduced histamine and serotonin activity
what is the PK of Scopolamine
SubQ or transdermal
change patch every 3 days
onset: 3-4 hours, duration: 72 hours
hepatic metabolism
what are the AE of scopolamine
tachy, fushing, dry mouth, blurred vision
cognitive imapirement
psychosis and hallucinations
what are the contraindications of scopolamine
narrow-angle glaucoma or with other agents containing belladonna
what are the D2 receptor antagonists
prochlorperazine
metocloperamide
what is the MOA of prochlorperazine
antagonizes D2 receptors in the CTZ and gut
also clocks M1 and H1 receptors
what is the PK of prochlorperazine
oral or rectal
duration: 1-2 hours oral, 3-12 hours rectal
what are the AE of prochlorperazine
extrapyramidal effects
tardive dyskinesia
hypotension
long QT
CNS effects
what are the uses of metocloperamide
chemo induced and post op N/V
documented gastroparesis
off label: tx of hiccups and n/v in early pregnancy
what is the MOA of metocloperamide
antagonizes D2 receptors in CTZ and gut
also blocks M1 and H1 receptors
weakly blocks 5-HT3 at high doses
what is the PK of metocloperamide
oral or IV
duration: 1-2 hours, dosed 3-4x/day
CYP2D6
what is the AE of metocloperamide
extrapyramidal effects
tardive dyskinesia
hypotension
long QT
CNS effects
hyperprolactinemia
what are the serotonin receptor antagonists for nausea/vomiting
Ondansetron
what are the uses of ondansetron
chemo induced N/V, mgmt of post-op N/V
effective alone or in combo with Dexamethasone
what is the MOA of ondansetron
selectively blocks 5-HT3 receptors in the periphery and brain
what is the PK of ondansetron
Oral or IV admin
onset: 30 min, peak 1-2 hours
extensively metab by liver, CYP
dose adjust in hepatically impairment
what are the AE of ondansetron
HA, dizziness, confusion, SOB, constipation, Long QT
monitor EKG and watch sings of serotonin syndrome
What is the Cannabinoids
Dronabinol
what is the use of dronabinol
second line for chemo-induced N/V
stimulate appetite in pts with AIDS
what is the MOA of Dronabinol
activates cannabinoid receptors
what is the PK of dronabinol
oral admin
onset: 30-60 min, peak 2-4 hours, duration 4-6 hours
hepatic metabolism
what are the AE of dronabinol
euphoria, CNS changes, abd pain, vomiting, flushing, hypotension, vertigo
what are the contraindications of Dronabinol
contra in psych disorders + SUB
monitor HR and BP, cannabis hyperemesis
What are the histamine antagonists
promethazine
meclizine
dimenhydrinate
what are the uses of promethazine
reduces emesis associated with surgery, chemo, and toxins
widely used in young children
motion sickness
what is the MOA of promethazine
blocks D2 receptors in CTZ
blocks H1 receptor in brainstem
what is the PK of promethazine
oral, IM or IV
duration 4-6 hours
CYP metabolism
what is the AE of promethazine
extramyramidal sx,
anticholinerigic effects
hypotension
sedation
EKG changes
photosensitivity
tissue injury
what is the use of Meclizine
OTC antihistamine
motion sickness
what is the MOA of meclizine
blocks H1 and M1 receptor - depresses labrynth excitability and vestibular stimulation
what is the PK of meclizine
oral onset: 1 hr, duration 24 hours
hepatic metabolism
what are the AE of meclizine
sedation, HA, vomiting, blurred vision
avoid in glaucoma, asthma, urinary retentions, pyloric/duodenal obstruction
what is the use of Dimenhydrinate
OTC antihistamine
motion sickness
what is the MOA of dimenhydrinate
blocks H1 receptors in peripheral sites and CTZ
has central anticholinergic activity
what is the PK of dimenhydrinate
oral and IM
onset 30 min, duration 4-6 hours
hepatic metabolism
what are the AE of dimenhydrinate
tachycardia
anorexia
epigastric distress
sedation
dizziness
xerostomia
blurred vision
SJS
CNS changes
what are the drug categories used for diarrhea and IBS-D
opioid agnosts
serotonin receptor modulators
bile acid sequestrants
anti-spasmodics
antimicrobial agents
what are the antidiarrheal medications
loperamide
diphenoxylate/atropine
octreotide
eluxadoline
alosetron
tegeserod
bile acid sequestrants
Rifaximin
hyoscyamine/dicyclomine
what are the opioid compund drugs
loperamide
diphenoxylate/atrophine
octreotide
eluxadoline
what is the MOA of opioid antagonists
activation of opioid receptors in the smooth muscle of the GI tract.
alters peristalsis by preventing smooth muscle contraction and relaxation.
reduces stool volume and can prevent electrolyte depletion
What are the uses of Loperamide
structural analog of peperidine
tx of diarrhea and reduce volume of discharge from ileostomies
what are the MOA of loperamide
activate opioid receptors in smooth muscle of the GI tract, alters peristalsis, reduces stool volume and prevents electrolyte depletion
increase IAS and EAS tone
what are the PK of loperamide
oral tablets or liquid admin
poorly absorbed and does not cross BB
Hepatic metabolism
what are the SE of loperamide
constipation, dizziness, abd pain and cramping
cardiac arrest when used in large doses
what are the uses of diphenoxylate/atropine
diarrhea
what are the MOA of diphenoxylate/atropine
activate opioid receptors in GI tract
atropine prevents abuse
what are the PK of diphenoxylate/atropine
tablet or liquid
hepatic metabolism
onset: 45 min, half life 2.5 hours
what are the SE of diphenoxylate/atropine
flushing, tachy, CNS effects, xeroderma, vomiting, toxic megacolon, urinary retention
what is octreotide used for
diarrhea
what is the MOA of octreotide
inhibits serotonin release and has some effect on opioid receptors
inhibits secretion of gastrin, VIP, insulin, glucagon, motilin, pancreatic polypeptide
what is the PK of octreotide
oral
duration 6-12 hours
hepatic metabolism
what are the AE of octreotide
brady, fatigue, HA, dizziness, pruitis, hyperglycemia, hypothyroidism
cholelithiasis, abd pain, diarrhea, constipation, biliary obstruction, URI, arrhythmia, depression
what is the use of Eluxadoline
approved for IBS-D
what is the MOA of Eluxadoline
blocks kappa, and delta opioid receptors in the intestinal lumen; activates mu receptors -> decrease intestinal motility without causing constipation
what are the PK of Eluxadoline
oral and half life of 4-6 hours
what are the AE of Eluxadoline
dizziness, drowsiness, nausea, abd pain, vomiting, elevated LFTs, URI
when is Eluxadoline contraindicated
alcohol abuse, hx of intestinal obstruction
what are the serotonin receptor modulators used for diarrhea
Alosetron and Tegaserod
what is the use of Alosetron
chronic (>6mo) severe IBS-D
what is the MOA of alosetron
selective serotonin antagonist
acts on receptors in enteric neurons and in other locations centrally and peripherally
what is the PK of Alosetron
oral admin, absorption rapid but incomplete
take on an empty stomach
extensive P450 metabolism
what are the AE of Alosetron
constipation, HA, fatigue, abdominal pain, nausea
when is Alosetron contraindicated
hx GI obstruction, Crohn’s disease, diverticulitis, vasculopathy, thrombophelbitis, hypercoagu conditions
what is Tegaserod used for
only available for emergency investigational drug purposes due to risk of cardiac arrest
what is the use of bile acid sequestrants
bile acid diarrhea